The brother of Ponzi scheme king Bernard Madoff will plead guilty on Friday to conspiracy and falsifying records, admitting his role in the multibillion-dollar fraud that destroyed the savings of thousands of investors, prosecutors told a judge on Wednesday.

Peter Madoff, the former chief compliance officer at the private investment arm of Bernard Madoff’s business, has agreed to serve a decade in prison, they said.

Peter Madoff also agreed to the criminal forfeiture of $143 billion, including all of his real estate and personal property. The $143 billion, representing the amount of money believed to have flowed through the business accounts when he was part of the multi-decade Ponzi scheme, is included in a criminal forfeiture agreement, though authorities know that his assets would never approach that figure.

Court papers signed by a federal judge in Manhattan on Wednesday show Peter Madoff, who had worked with his brother since 1965, will plead guilty to two criminal counts, admitting his role in a conspiracy to commit securities fraud, falsify records of an investment adviser, falsify records of a broker dealer, make false filings with the Securities and Exchange Commission, commit mail fraud and obstruct the Internal Revenue service.

Assistant U.S. Attorney Lisa A. Baroni wrote in a letter to U.S. District Judge Laura Taylor Swain that, pursuant to a plea agreement with the government, Madoff, 66, had agreed “not to seek a sentence other than 10 years’ imprisonment.”

A lawyer for Madoff, Charles Spada, declined to comment on Wednesday.

Bernard Madoff, 74, is serving a 150-year prison sentence in Butner, N.C., after revealing in December 2008 that he cheated thousands of investors of roughly $20 billion for years, using money from new investors to pay returns to existing clients. A $171 billion forfeiture order entered against Madoff forced him to relinquish tens of millions of dollars in personal property, including real estate, investments and $80 million in assets his wife had claimed were hers. The $171 billion represented the total amount of money that went through the company during the fraud.

Lawyers for a court-appointed trustee recovering money for Bernard Madoff’s investors had said Peter Madoff also was the company’s senior managing director.

The trustee, Irving Picard, said in court papers that Peter Madoff “failed miserably” to meet his responsibilities to monitor the company’s operations and ensure its compliance with federal securities laws.

The court papers said Peter Madoff had received at least $60 million during the fraud and used fake stock trades to make large withdrawals seem justified.

Picard sought nearly $200 million from Madoff family members, claiming they used Bernard L. Madoff Investment Securities LLC as “the family piggy bank” to pay for vacation homes, cars, boats and even a stake in a beauty parlor.

Picard’s pending lawsuit alleges that over the years Peter Madoff, his daughter and his nephews “withdrew millions more than they invested” in private investment accounts they had with the firm.

Peter Madoff “ignored obvious red flags that the profits reflected in account statements could not have been earned legitimately, to the detriment of BLMIS and its other customers,” the lawsuit says.

Bernard Madoff’s relatives have said they did not know about his Ponzi scheme. The new plea raises new questions about the status of the prosecution and whether other family members are being targeted by the government.

Lawyers for Andrew Madoff, a son of Bernard Madoff; Ruth Madoff, Bernard Madoff’s wife; and Shana Madoff, Peter Madoff’s daughter, did not immediately return messages seeking comment on Wednesday. Mark Madoff, Bernard Madoff’s other son, committed suicide in December 2010 on the second anniversary of his father’s arrest.

Six former employees and associates have pleaded guilty and are cooperating with authorities. Five others, including Madoff’s former operating chief, have pleaded not guilty and appear headed to trial.

Picard has accused Andrew Madoff of living a high-end lifestyle after receiving more than $60 million, including $31 million in salary and bonus, from 2001 to 2008.

Shana Madoff, a lawyer, had worked at Madoff’s investment business since 1995 as compliance counsel and in-house counsel. Picard’s civil lawsuit said that “she ignored every red flag of the massive fraud taking place right in front of her.”

The massive scheme, run since at least the early 1990s, demolished the life savings of thousands of people, wrecked charities and shook confidence in the U.S. financial system. When Bernard Madoff pleaded guilty, he insisted that he acted alone, describing a separate wholesale stock-trading firm run by his sons and brother as honest and legitimate.

Picard’s office has reached agreements to recover approximately $9.1 billion and has distributed more than $1.1 billion to Madoff’s victims.

In a statement Wednesday, Picard’s spokeswoman, Amanda Remus, said the trustee and his lawyers are aware of the letter to the court about the anticipated guilty plea proceeding involving Peter Madoff but had no comment.